The present invention relates to a light source device for a projector, which is installed in a projector apparatus equipped with a spatial modulation element, such as a liquid crystal display device and a digital micromirror device.
In recent years, a projector apparatus equipped with a spatial modulation element, such as a liquid crystal display device and a digital micromirror device, has been developed. One example of a projector apparatus is a color sequential display type projector apparatus in which three primary color lights are formed by dividing, in terms of time, white light emitted from a white light source by a color wheel to display a full color image by irradiating each pixel with the three primary color lights one by one (Japanese Patent No. 3896074).
FIG. 5 is an explanatory diagram showing the structure of an example of a color sequential display type projector apparatus. The projector apparatus 80 comprises a light source lamp 81 that emits white light, an elliptical reflection mirror 82 that condenses the light emitted from light source lamp 81, a color wheel 83, which is driven to rotate, and which divides, in terms of time, the light emitted from the light source lamp 81 to form three primary color lights and white light, a rod integrator 84 for receiving and uniformizing the light that passes through the color wheel 83, a flat reflection mirror 85 that reflects the light emitted from the rod integrator 84, a reflection type spatial modulation element 86 that the light from the flat reflection mirror 85 enters so that a light image is emitted therefrom, a spatial modulation element actuator 87 that drives the spatial modulation element 86, and a projection lens 88 that projects the light image emitted from the spatial modulation element 86 on a screen. The color wheel 83 comprises a filter element 83b that transmits blue light, a filter element 83r that transmits red light, a filter element 83g that transmits green light, and a filter element 83w that transmits white light, wherein these filter elements are respectively in a shape of a partial sector and are arranged to form an annular shape on the same plane.
In such a projector apparatus 80, when the white light emitted from the light source lamp 81 passes through the color wheel 83, the white light is divided into four in terms of time, thereby forming white light and three primary color lights which are blue light, red light, and green light. Then, when these primary color lights and the white light enter the spatial modulation element 86 one by one through the rod integrator 84 and the flat reflection mirror 85, a light image made up of the respective primary color lights and the white light forms. And when the light image is projected sequentially on the screen through the projection lens 88, a desired color image is formed on the screen.